Showing papers by "Institut national de la recherche agronomique published in 1984"

Isoflavonoid accumulation in soybean roots infected with vesicular-arbuscular mycorrhizal fungi

Abstract: Roots ofsoybean (Glycine max cv. Amsoy 71) were analysed for their contents of stress metabolites 4, 6 and 8 weeks after the plants had been inoculated with different vesicular-arbuscular (VA) endomycorrhizal fungi (Glomus mosseae or Glomus fasciculatus or a mixture of the two) or 2 and 4 days after treatment with CuSO4 (10−3 m). All these treatments increased the concentrations of three isoflavonoids: glyceollin I, coumestrol and diadzein. The concentration of the phytoalexin glyceollin was greater in mycorrhizal infected roots than in non-mycorrhizal roots, but the amounts present were always low (< 1·0 μg g−1 fresh weight). The amounts of coumestrol and daidzein found in mycorrhizal roots varied between 7 and 34 μg g−1 fresh weight. The results are discussed in relation to the reported reduction of soil-borne disease caused by VA endomycorrhizal infection of plants.

Inhibition of alcoholic fermentation of grape must by Fatty acids produced by yeasts and their elimination by yeast ghosts.

Abstract: In a complete nutritive medium rich in sugar, such as grape must, the inhibition of alcoholic fermentation is caused by substances produced by the yeast which, acting synergistically with ethanol, are toxic to the yeasts themselves. Among these are decanoic and octanoic acids and their corresponding ethyl esters. Their adsorption by yeast ghosts permits the prevention and treatment of fermentation stoppages.

Evolution of acetic Acid bacteria during fermentation and storage of wine.

Abstract: Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of Gluconobacter oxydans, Acetobacter pasteurianus, and Acetobacter aceti during the course of these stages was noted. Low levels of A. aceti remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH favored the development and metabolism of these species.

Studies of the nature of the interaction between vasopressin and corticotropin-releasing factor on adrenocorticotropin release in the rat.

Abstract: Arginine-vasopressin (AVP) acts on vasocon-striction and diuresis through two different types of receptors (V1 and V2, respectively). Since AVP also modifies ACTH release, we have attempted to determine which class of receptors mediates the capacity of AVP to increase ACTH secretion and o t potentiate the effect of corticotropin-releasing factor (CRF) on the pituitary using two AVP antagonists: [1-deaminopenicil-lamine-2-(O-methyl)tyrosine]arginine-vasopressin [dPTyr(Me)-AVP], which blocks Vi receptors, and [1-(β-mercapto-β,β-cyclo-pentamethylene propionic acid)2-d-leucine-4-valine]arginine vasopressin [d(CH2)6DLeuValAVP], which interferes with V2 receptors. dPTyr(Me)AVP, but not d(CH2)6DLeuValAVP, in-hibited the ACTH-releasing as well as the CRF-potentiating effects of both AVP and its antidiuretic analog [1-deamino-8-d-argininejvasopressin (dDAVP). These results suggest that the actions of AVP and dDAVP on the corticotrophs is primarily mediated through V1 (pressor-like) receptors. (Endocrinology 115: 8...

Energy and Protein Utilization in Growing Cattle

Abstract: Limited data are available to describe the different phases of dietary protein and energy utilization in growing cattle as compared with those in adult cattle or in growing nonruminants. The European data on this topic are summarized to indicate application in appropriate feeding standards. Net protein requirements are widely variable with breed and sex. They are lower in steers than in bulls and lower in early maturing than in late maturing breeds. They are clearly defined for growing and fattening bulls where they are influenced by breed, live weight and live weight gain. New systems have been proposed to express the protein allowances. They provide a great step towards a concept explaining N supply to ruminants. However, protein degradability in the rumen, efficiency of microbial protein synthesis, intestinal digestibility and metabolic efficiency of amino acid absorption in the intestine need to be described more accurately. Even if body energy retention measured by the slaughter technique is systematically lower than when measured by calorimetric balance, both techniques can correctly describe the effect of breed sex, weight, or daily gain on energy retained, in relative value, and its distribution between protein and fat deposition. But further research is needed to confirm the distribution of metabolizable energy between maintenance and growth and the efficiency of metabolizable energy utilization for growth. Thus, different authors have preferred to calculate the energy allowances, not by a factorial method, but by regression between energy intake and the corresponding weight and daily gain of animals measured during feeding trials.

Induction of pituitary lactotrope differentiation by luteinizing hormone alpha subunit

Abstract: Addition of gonadotropin releasing hormone to cultures of fetal rat pituitary induced differentiation of lactotropes as revealed by immunocytochemistry. Antiserum to luteinizing hormone (LH) (recognizing native LH), but not antiserum to LH-beta (recognizing both native LH and its beta subunit), inhibited this induction. Further addition of highly purified LH-alpha subunit in culture medium also induced lactotrope differentiation. Thus, the alpha subunit may have a specific biological activity of its own with probable practical use in clinical investigations.

Fouling of a plate heat exchanger used in ultra-high-temperature sterilization of milk

Abstract: The composition and weight of deposit formed in all sections of an ultra-high-temperature milk sterilization plant were determined. Deposits formed in the preheating, heating and cooling sections during sterilization of pasteurized whole milk were analysed for dry matter, protein, fat and mineral contents. The weight and composition of components of the deposit varied in different sections of the plant and with the heating temperature. Two categories of deposit could be distinguished: one in the preheating section consisting of (w/w) protein 50%, minerals 40% and fat 1% and another in the heating section consisting of minerals 75%, proteins 15% and fat 3%. Concerning the rate of formation of these deposits, a comparison of the results with those obtained for pasteurization shows that fouling was more rapid during pasteurization of raw milk than during sterilization of previously pasteurized milk. Hypotheses concerning mechanisms of formation of protein deposition are discussed.

Diallel analysis of androgenetic plant production in hexaploid Triticale (X. triticosecale, Wittmack).

Abstract: Studies were made on the genetic determination of androgenetic plant yield and its two components: embryo production and green plant regeneration. This involved the analysis of a complete 7×7 diallel cross of 4 androgenetic lines and 3 lines obtained by pedigree selection, one of them having the Triticum timopheevi cytoplasm. The three traits analysed are both heritable and environmentally influenced (by season and culture medium composition). The analysis of embryo production shows a mainly nuclear inheritance, with predominantly additive gene action, but also a favourable effect of Triticum timopheevi cytoplasm. Green plant regeneration has a more complex genetic determination, with additive as well as non-additive gene action and cytoplasmic influences. Hybrids appear superior to inbred lines for embryogenesis and green plant yield, but not for green plant regeneration. Androgenetic lines used as parents did not show superiority over other parents either in their own value or in the transmission of androgenetic abilities. Genetic improvement seems to be possible by recombination in progenies of hybrids between lines having complementary abilities.

Plasma Lipoprotein Profile in Fasted and Refed Chickens of Two Strains Selected for High or Low Adiposity

Abstract: The plasma lipoprotein profile has been determined in fasted and refed 5-week-old male broilers selected for low or high adiposity. Lipoprotein classes were subfractionated by density gradient ultracentrifugation, appearing as distinct bands with the following densities: very low density lipoprotein (VLDL), d less than 1.013 g/ml; low density lipoprotein (LDL), d 1.023-1.046 g/ml and high density lipoprotein (HDL), d 1.052-1.130 g/ml; the physiochemical characteristics (chemical composition, electrophoretic mobility and particle size) of these particles were then assessed. HDL, seen as a single band, represented 80% of total lipoproteins, with VLDL and LDL accounting for 1% and 16%, respectively, in fasted birds. Lipoprotein profiles were similar in fasted and refed animals of both lines, with the exception that VLDL levels were some 14-fold and 7-fold higher in the lean and fat lines, respectively, in the refed state. The VLDL of fasted birds of both lines were enriched in protein and relatively homogeneous in size; by contrast, VLDL in the refed state contained more triglyceride and less cholesteryl ester and protein and were larger and more heterogeneous, possibly representing a mixture of portomicrons and VLDL of hepatic origin. Birds of the fat line in both nutritional states differed from lean birds in exhibiting elevated plasma lipid and lipoprotein [VLDL, intermediate density lipoprotein (IDL) and HDL] levels, evidence that liver activity is directed toward increased lipoprotein production and secretion in that line.

Host-Fungus Specificity, Recognition and Compatibility in Mycorrhizae

Abstract: Susceptibility in plants to parasites (for definition see Vanderplank, 1978) is considered to be a relatively rare phenomenon in nature; a striking exception to this rule is found in mycorrhizal associations. Mycorrhizae, a term describing a range of mutualistic associations between soil fungi and plant roots, are no doubt the most frequent examples of compatibility between plants and microbes. The mycorrhizal habit has a long evolutionary history (Nicolson, 1975, Pirozynski and Malloch, 1975, Boullard, 1979) and today more than 90% of all plant taxa, ranging from thallophytes to angiosperms, form associations of one type or another with mycorrhizal fungi. Only a small number of plant species belonging mainly to the Cuperaceae, Chenopodiaceae, Cruciferae, Juncaceae and Proteaceae are nonmycorrhizal and can be considered as incompatible towards mycorrhizal fungi. A characteristic feature of the fungi forming mycorrhizae is that, although they are generally widespread in soils, they exhibit a strong biotrophic dependence on their host plants and are rarely free-living saprophytes.

Ultrastructural aspects of in vivo fertilization in the cow

Abstract: In vivo fertilization of cow eggs has been studied by electron microscopy. Eggs were recovered from intracervically inseminated heifers 30 to 42 hr after the onset of oestrus. The corona cells remained attached to 4 out of the 15 eggs studied, but no sign of sperm phagocytosis was noted. Spermatozoa close to the zona pellucida, but not in contact with it, were not acrosome reacted. In contrast, all sperm penetrating the zona pellucida had completed the acrosome reaction. Vesiculated products of the reaction were present at the zona surface of every penetrated egg, indicating that in this species, the acrosome reaction occurs at the surface of the zona pellucida. During sperm passage through the zona pellucida, the equatorial segment overlaid by its plasma membrane remained intact. Soon after penetration into the ooplasm, the sperm nucleus decondensed; at the same time, the female chromosomes resulting from the second meiotic division aggregated in a few masses of condensed chromatin. A nuclear envelope started to form around the condensed female chromatin, while it was not yet present around the decondensing male nucleus. After swelling, the two pronuclei presented similar ultrastructural morphology; they contained small, compact, agranular nucleoli with a large fibrillar center and unevenly distributed chromatin. The pronuclear envelope contained pores and presented characteristic blebbing. The endoplasmic reticulum was closely apposed to the nuclear envelope and large Golgi structures were proximal to the pronuclei.

Inheritance of zucchini yellow mosaic virus resistance in Cucumis melo L.

Abstract: Resistance to zucchini yellow mosaic virus has been found in the muskmelon line ‘PI 414723’ from India. This resistance is effective against the ZYMV strains E15 and 1318 belonging respectively to the NF and F pathotypes. Resistance to E15 (no vein clearing and yellowing symptoms) is governed by one dominant gene (symbol Zym) according to segregations observed in F1, F2 and BC1 progenies. This gene is epistatic dominant over Fn, which induces wilting and necrosis after inoculation with F pathotype. Linkage studies suggest that Zym inherits independently from Fom-1, Fom-2, Vat, Wmv and Fn but is linked with a (13.1 ±2.4 units).

Factors influencing the variation of some properties of soils in relation to their suitability for direct drilling

Abstract: Soils from fifteen field experiments in the United Kingdom and one in France that compared direct drilling with mouldboard ploughing were examined with respect to their composition and physical properties. Indices of the stability and shrinkage of soil aggregates were obtained by measurement and an index of compactability was derived from an established relationship. It was hypothesized that these properties were possible determinants of soil responses to zero-tillage. Aggregate stability and shrinkage were correlated with organic carbon and clay content, respectively. Organic matter contents were greater at the surface of direct-drilled soils than in the complete topsoil layer after direct drilling or ploughing. In some cases the increase in organic matter significantly improved the physical properties of the soils. The three indices, of stability, shrinkage and compactability, were each ranked in high intermediate or low groups, and the soils classified according to their ratings in these groups. The resulting classification broadly agreed with a previous one of soil suitability for sequential direct drilling mainly based on experimental agronomy.

Molecular relationships between virulence plasmids of Salmonella serotypes typhimurium and dublin and large plasmids of other Salmonella serotypes.

Abstract: Summary All studied isolates of Salmonella serotypes abortusovis (16 strains), enteritidis (30 strains), paratyphi C (29 strains), and 2 out of 10 isolates of serotype newport harboured large 54–76-Kb plasmids. No such plasmids were found in the following serotypes: agona, bovismorbificans, heidelberg, infantis, panama, paratyphi A, paratyphi B, saintpaul, senftenberg and typhi. These plasmids and the virulence-associated plasmids of Salmonella serotypes typhimurium and dublin were compared at the molecular level. Plasmids from the same serotype usually showed similar Hin dIII endonuclease patterns. Plasmids from different serotypes displayed markedly different cleavage patterns. Using the 3 H-labelled plasmid from serotype typhimurium strain C5 as a probe, nitrocellulose filter hybridization showed that all these plasmids shared homologous sequences distributed throughout the plasmid molecule. With the S1-nuclease method, all plasmids were 61 to 88% related to the virulence plasmid of serotype typhimurium strain C5. The large plasmids in Salmonella serotypes abortusovis, enteritidis, paratyphi C, newport and the virulence-associated plasmids in serotypes typhimurium and dublin thus constitute a single group of homology and represent a family of related plasmids. We suggest that this plasmid group may contribute to the pathogenic potential of host serotypes.

Prostaglandin E2: a neuromodulator in the central control of gastrointestinal motility and feeding behavior by calcitonin

Abstract: Two micrograms of prostaglandin E2 injected into the lateral ventricle of the brain in rats had the same anorectic and gastrointestinal motor effect as central administration of 0.02 unit of calcitonin. The effects of calcitonin were blocked by a previous intracerebroventricular administration of 0.25 milligram of indomethacin. These results suggest that both anorectic and gastrointestinal motor effects of calcitonin are centrally mediated by the release of prostaglandins.

Primary structure of the ram (Ovis aries) protamine

Abstract: The amino acid sequence of the protamine isolated from mature sperm nuclei of the ram (Ovis aries) has been established from automated sequence analysis of the S-carboxymethylated protamine. Ram and bull protamines differ only by two point changes and the deletion in bull protamine of the tripeptide Cys39-Arg-Arg41. In mammalian protamines the central region (residues 13–36) consisting mainly of arginine clusters appears to be conserved whereas the N-terminal and C-terminal regions are more variable.

Ratio of free to bound polyamines during maturation in mung-bean hypocotyl cells

Abstract: Free- and bound-polyamine levels were estimated in successive segments of the mung-bean hypocotyl. Three aliphatic polyamines (putrescine, spermidine and spermine) were found in proportions which depended on the state of maturation. In young cells, most of the polyamines were located in the protoplasm whereas in older cells they were mostly bound to the cell walls. Spermidine was always the main bound polyamine, and putrescine, the main free polyamine.

Dosage de la lignine insoluble en milieu acide: influence du pretraitement par hydrolyse acide sur la lignine Klason de bois et de paille.

Abstract: Un protocole de dosage de la lignine insoluble dans l'acide sulfurique concentre, lignine Klason, est decrit : il comporte une etape de prehydrolyse par l'acide sulfurique 5 % et un lavage, en milieu chlorhydrique concentre, du residu de prehydrolyse. Ce lavage permet d'ameliorer la reproductibilite du dosage de la lignine apres prehydrolyse et d'atteindre une reproductibilite comparable a celle obtenue par le dosage Klason standard. L'analyse elementaire des preparations de lignines isolees au cours de ces dosages indique des variations complexes qui dependent de la nature du produit analyse.

Large-scale purification and characterisation of pea globulins

Abstract: Pea globulins, vicilin and legumin were isolated by chromatography on DEAE Sepharose and Ultrogel ACA 34. The procedure was carried out on a preparative scale and used to purify about 5 g of each globulin for a separation cycle. The purity of the vicilin and legumin was verified by immunoelectrophoretic and ultracentrifuge analysis.